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Rouffaer LO, Baert K, Van den Abeele AM, Cox I, Vanantwerpen G, De Zutter L, Strubbe D, Vranckx K, Lens L, Haesebrouck F, Delmée M, Pasmans F, Martel A. Low prevalence of human enteropathogenic Yersinia spp. in brown rats (Rattus norvegicus) in Flanders. PLoS One 2017; 12:e0175648. [PMID: 28403184 PMCID: PMC5389835 DOI: 10.1371/journal.pone.0175648] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 03/29/2017] [Indexed: 11/18/2022] Open
Abstract
Brown rats (Rattus norvegicus) have been identified as potential carriers of Yersinia enterocolitica and Y. pseudotuberculosis, the etiological agents of yersiniosis, the third most reported bacterial zoonosis in Europe. Enteropathogenic Yersinia spp. are most often isolated from rats during yersiniosis cases in animals and humans, and from rats inhabiting farms and slaughterhouses. Information is however lacking regarding the extent to which rats act as carriers of these Yersinia spp.. In 2013, 1088 brown rats across Flanders, Belgium, were tested for the presence of Yersinia species by isolation method. Identification was performed using MALDI-TOF MS, PCR on chromosomal- and plasmid-borne virulence genes, biotyping and serotyping. Yersinia spp. were isolated from 38.4% of the rats. Of these, 53.4% were designated Y. enterocolitica, 0.7% Y. pseudotuberculosis and 49.0% other Yersinia species. Two Y. enterocolitica possessing the virF-, ail- and ystA-gene were isolated. Additionally, the ystB-gene was identified in 94.1% of the other Y. enterocolitica isolates, suggestive for biotype 1A. Three of these latter isolates simultaneously possessed the ail-virulence gene. Significantly more Y. enterocolitica were isolated during winter and spring compared to summer. Based on our findings we can conclude that brown rats are frequent carriers for various Yersinia spp., including Y. pseudotuberculosis and (human pathogenic) Y. enterocolitica which are more often isolated during winter and spring.
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Farrer RA, Martel A, Verbrugghe E, Abouelleil A, Ducatelle R, Longcore JE, James TY, Pasmans F, Fisher MC, Cuomo CA. Genomic innovations linked to infection strategies across emerging pathogenic chytrid fungi. Nat Commun 2017; 8:14742. [PMID: 28322291 PMCID: PMC5364385 DOI: 10.1038/ncomms14742] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 01/26/2017] [Indexed: 11/09/2022] Open
Abstract
To understand the evolutionary pathways that lead to emerging infections of vertebrates, here we explore the genomic innovations that allow free-living chytrid fungi to adapt to and colonize amphibian hosts. Sequencing and comparing the genomes of two pathogenic species of Batrachochytrium to those of close saprophytic relatives reveals that pathogenicity is associated with remarkable expansions of protease and cell wall gene families, while divergent infection strategies are linked to radiations of lineage-specific gene families. By comparing the host–pathogen response to infection for both pathogens, we illuminate the traits that underpin a strikingly different immune response within a shared host species. Our results show that, despite commonalities that promote infection, specific gene-family radiations contribute to distinct infection strategies. The breadth and evolutionary novelty of candidate virulence factors that we discover underscores the urgent need to halt the advance of pathogenic chytrids and prevent incipient loss of biodiversity. Batrachochytrium dendrobatidis and B. salamandrivorans are both important pathogens of amphibians, but they differ in their host ranges, infection strategies, and host immune responses. Here, Farrer and colleagues compare their genomes and transcriptomes to identify the genetic basis of these differences.
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Antonissen G, Devreese M, De Baere S, Martel A, Van Immerseel F, Croubels S. Impact of Fusarium mycotoxins on hepatic and intestinal mRNA expression of cytochrome P450 enzymes and drug transporters, and on the pharmacokinetics of oral enrofloxacin in broiler chickens. Food Chem Toxicol 2017; 101:75-83. [DOI: 10.1016/j.fct.2017.01.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 12/19/2016] [Accepted: 01/05/2017] [Indexed: 11/16/2022]
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Abstract
Neoplasieën van de pigmentcellen of chromatoforen bij reptielen worden naargelang hun oorsprong geclassificeerd als melanoforoma’s, iridoforoma’s, xantoforoma’s, erytroforoma’s of gemengde chromatoforoma’s. In tegenstelling tot wat oorspronkelijk verondersteld werd, komen deze primaire, cutane neoplasieën regelmatig voor bij in gevangenschap gehouden reptielen. Melanoforoma’s en iridoforoma’s worden het meest frequent vastgesteld. Een definitieve diagnose van chromatoforoma’s wordt bekomen door middel van histologisch onderzoek. Aanvullend is immunohistochemie of elektronenmicroscopie soms noodzakelijk om chromatoforoma’s onderling te differentiëren. Complete chirurgische excisie wordt beschouwd als de voorkeursbehandeling. Vanwege de uitgesproken maligniteit en neiging tot metastasering is de prognose van chromatoforoma’s bij reptielen over het algemeen echter sterk gereserveerd. Een vroegtijdige en correcte diagnose van deze neoplastische aandoening bij reptielen is daarom van primordiaal belang. In dit artikel wordt een overzicht gegeven van de huidige kennis omtrent het voorkomen, het biologisch gedrag, de pathogenese en de diagnostische en therapeutische benadering van chromatoforoma’s bij reptielen met de nadruk op melano- en iridoforoma’s.
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Rosa GM, Sabino-Pinto J, Laurentino TG, Martel A, Pasmans F, Rebelo R, Griffiths RA, Stöhr AC, Marschang RE, Price SJ, Garner TWJ, Bosch J. Impact of asynchronous emergence of two lethal pathogens on amphibian assemblages. Sci Rep 2017; 7:43260. [PMID: 28240267 PMCID: PMC5327436 DOI: 10.1038/srep43260] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 01/17/2017] [Indexed: 12/15/2022] Open
Abstract
Emerging diseases have been increasingly associated with population declines, with co-infections exhibiting many types of interactions. The chytrid fungus (Batrachochytrium dendrobatidis) and ranaviruses have extraordinarily broad host ranges, however co-infection dynamics have been largely overlooked. We investigated the pattern of co-occurrence of these two pathogens in an amphibian assemblage in Serra da Estrela (Portugal). The detection of chytridiomycosis in Portugal was linked to population declines of midwife-toads (Alytes obstetricans). The asynchronous and subsequent emergence of a second pathogen - ranavirus - caused episodes of lethal ranavirosis. Chytrid effects were limited to high altitudes and a single host, while ranavirus was highly pathogenic across multiple hosts, life-stages and altitudinal range. This new strain (Portuguese newt and toad ranavirus – member of the CMTV clade) caused annual mass die-offs, similar in host range and rapidity of declines to other locations in Iberia affected by CMTV-like ranaviruses. However, ranavirus was not always associated with disease, mortality and declines, contrasting with previous reports on Iberian CMTV-like ranavirosis. We found little evidence that pre-existing chytrid emergence was associated with ranavirus and the emergence of ranavirosis. Despite the lack of cumulative or amplified effects, ranavirus drove declines of host assemblages and changed host community composition and structure, posing a grave threat to all amphibian populations.
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Kilroy S, Raspoet R, Martel A, Bosseler L, Appia-Ayme C, Thompson A, Haesebrouck F, Ducatelle R, Van Immerseel F. Salmonella Enteritidis flagellar mutants have a colonization benefit in the chicken oviduct. Comp Immunol Microbiol Infect Dis 2017; 50:23-28. [PMID: 28131374 DOI: 10.1016/j.cimid.2016.11.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 07/28/2016] [Accepted: 11/07/2016] [Indexed: 10/20/2022]
Abstract
Egg borne Salmonella Enteritidis is still a major cause of human food poisoning. Eggs can become internally contaminated following colonization of the hen's oviduct. In this paper we aimed to analyze the role of flagella of Salmonella Enteritidis in colonization of the hen's oviduct. Using a transposon library screen we showed that mutants lacking functional flagella are significantly more efficient in colonizing the hen's oviduct in vivo. A micro-array analysis proved that transcription of a number of flagellar genes is down-regulated inside chicken oviduct cells. Flagella contain flagellin, a pathogen associated molecular pattern known to bind to Toll-like receptor 5, activating a pro-inflammatory cascade. In vitro tests using primary oviduct cells showed that flagellin is not involved in invasion. Using a ligated loop model, a diminished inflammatory reaction was seen in the oviduct resulting from injection of an aflagellated mutant compared to the wild-type. It is hypothesized that Salmonella Enteritidis downregulates flagellar gene expression in the oviduct and consequently prevents a flagellin-induced inflammatory response, thereby increasing its oviduct colonization efficiency.
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Nguyen TT, Nguyen TV, Ziegler T, Pasmans F, Martel A. Trade in wild anurans vectors the urodelan pathogen Batrachochytrium salamandrivorans into Europe. AMPHIBIA-REPTILIA 2017. [DOI: 10.1163/15685381-00003125] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Pathogen pollution has caused dramatic losses of amphibian diversity on a global scale. The recently emerged chytrid fungus Batrachochytrium salamandrivorans (Bsal) has been hypothesized to have its origin in Asian urodelan populations, from which it may have been introduced to Europe through the trade in live urodelans. We here show that Bsal is present on wild small-webbed fire-bellied toads (Bombina microdeladigitora) from Vietnam and on representatives of the same species that have recently been imported in Germany. This finding suggests that the installment of measures to mitigate the Bsal threat through the amphibian trade should not be limited to urodeles, but should equally take anurans into account.
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Salvidio S, Pasmans F, Bogaerts S, Martel A, van de Loo M, Romano A. Consistency in trophic strategies between populations of the Sardinian endemic salamander Speleomantes imperialis. ANIM BIOL 2017. [DOI: 10.1163/15707563-00002517] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The study of trophic ecology of terrestrial salamanders is central for a better understanding of their adaptability and dispersal, in particular in Mediterranean ecosystems where their feeding activity is reduced because of prolonged arid periods. Terrestrial salamanders are generalist predators that feed on a large array of invertebrate prey groups, however, there are few studies comparing the feeding strategy and the trophic specialization at the individual level in conspecific populations of salamanders living in different habitats. In this study, two populations of the Sardinian endemic salamander Speleomantes imperialis were sampled in areas characterized by different climate, vegetation and geological substrate. Dietary habits, obtained by stomach flushing, and physiological condition, assessed through a body condition index, were analysed and compared between populations. The two populations displayed different diets on the basis of the taxonomic composition of prey categories, but both of them behaved as generalist predators and shared a similar body condition index. Moreover, in both populations the indices of individual trophic specialization were significantly different from null models assuming a random prey distribution among predators. Therefore, the two populations were largely composed by individually specialized salamanders. Overall, these findings are in good agreement with other studies on the trophic ecology of top predators and in particular of terrestrial salamanders. The realized trophic strategies, i.e. generalist at the population and specialist at the individual level, were highly consistent geographically and the two populations exploited the different arrays of prey found in their environments similarly.
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Stark T, Laurijssens C, Weterings M, Martel A, Köhler G, Pasmans F. Prevalence of Batrachochytrium dendrobatidis in a Nicaraguan, micro-endemic Neotropical salamander, Bolitoglossa mombachoensis. AMPHIBIA-REPTILIA 2017. [DOI: 10.1163/15685381-00003077] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Amphibians are the most threatened terrestrial vertebrates on the planet and are iconic in the global biodiversity crisis. Their global decline caused by the fungal agentBatrachochytrium dendrobatidis(Bd) is well known. Declines of Mesoamerican salamanders of the family Plethodontidae, mainly affecting high elevation species, have equally been attributed toBd. Here we report the prevalence ofBdin a population of a high elevationBolitoglossaspecies in Nicaragua, since its description in 1999 until 2011 in the absence of any obvious population declines. Our findings show a low prevalence in an environmental context where pathogen driven declines would be expected to occur.
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Antonissen G, Haesendonck R, Devreese M, Broekaert N, Verbrugghe E, De Saeger S, Audenaert K, Haesebrouck F, Pasmans F, Ducatelle R, Croubels S, Martel A. The Impact of Deoxynivalenol on Pigeon Health: Occurrence in Feed, Toxicokinetics and Interaction with Salmonellosis. PLoS One 2016; 11:e0168205. [PMID: 27997572 PMCID: PMC5172580 DOI: 10.1371/journal.pone.0168205] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 11/28/2016] [Indexed: 12/26/2022] Open
Abstract
Seed-based pigeon diets could be expected to result in exposure of pigeons to mycotoxins such as deoxynivalenol (DON). Ingestion of low to moderate contamination levels of DON may impair intestinal health, immune function and/or pathogen fitness, resulting in altered host-pathogen interactions and thus different outcome of infections. Here we demonstrate that DON was one of the most frequently detected mycotoxins in seed-based racing pigeons feed, contaminating 5 out of 10 samples (range 177–1,466 μg/kg). Subsequently, a toxicokinetic analysis revealed a low absolute oral bioavailability (F) of DON in pigeons (30.4%), which is comparable to other avian species. Furthermore, semi-quantitative analysis using high-resolution mass spectrometry revealed that DON-3α-sulphate is the major metabolite of DON in pigeons after intravenous as well as oral administration. Following ingestion of DON contaminated feed, the intestinal epithelial cells are exposed to significant DON concentrations which eventually may affect intestinal translocation and colonization of bacteria. Feeding pigeons a DON contaminated diet resulted in an increased percentage of pigeons shedding Salmonella compared to birds fed control diet, 87 ± 17% versus 74 ± 13%, respectively. However, no impact of DON was observed on the Salmonella induced disease signs, organ lesions, faecal and organ Salmonella counts. The presented risk assessment indicates that pigeons are frequently exposed to mycotoxins such as DON, which can affect the outcome of a Salmonella infection. The increasing number of pigeons shedding Salmonella suggests that DON can promote the spread of the bacterium within pigeon populations.
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Haesendonck R, Garmyn A, Dorrestein GM, Hellebuyck T, Antonissen G, Pasmans F, Ducatelle R, Martel A. Marek's disease virus associated ocular lymphoma in Roulroul partridges (Rollulus rouloul). Avian Pathol 2016; 44:347-51. [PMID: 26021782 DOI: 10.1080/03079457.2015.1056088] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Two 1-year old Roulroul partridges (Rollulus rouloul), one male and one female, were presented because of eye problems and anorexia. Twenty of the 30 Roulroul partridges in the owner's collection had already died. The affected birds stopped eating, became thinner, and eventually died. Antibiotic treatment, which started because of the suspicion of a septicaemic process, was unsuccessful. At clinical examination of the two partridges it was found that in both birds, one eye ball was filled with a whitish yellow amorphous material and the other eye ball of the female showed a distinct corneal opacity. Both presented birds were euthanized. Necropsy revealed no significant abnormalities in addition to the eye lesions. Histology and immunohistochemistry of the female's eye revealed an infiltrate of T-lymphocytes corresponding to ocular lymphoma. Herpesvirus genus-specific PCR, followed by Sanger sequencing confirmed the presumptive diagnosis of Marek's disease in both birds. To our knowledge, this is the first confirmed case of infection with Gallid Herpesvirus 2 (Marek's disease virus) in partridges and the first case in this specific species.
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Spitzen-van der Sluijs A, Pasmans F, Struijk RP, Schils M, Doornbos P, van der Sterren F, Rijks J, Kik M, Saucedo B, Bosman W, Martel A. Course of an Isolated Ranavirus Outbreak in a Pelobates fuscus Population in The Netherlands. ACTA ACUST UNITED AC 2016. [DOI: 10.5818/1529-9651-26.3-4.117] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Dunne O, Weidenhaupt M, Callow P, Martel A, Moulin M, Perkins SJ, Haertlein M, Forsyth VT. Matchout deuterium labelling of proteins for small-angle neutron scattering studies using prokaryotic and eukaryotic expression systems and high cell-density cultures. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2016; 46:425-432. [PMID: 27844110 PMCID: PMC5486828 DOI: 10.1007/s00249-016-1186-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 10/19/2016] [Accepted: 10/28/2016] [Indexed: 12/17/2022]
Abstract
Small-angle neutron scattering (SANS) is a powerful technique for the characterisation of macromolecular structures and interactions. Its main advantage over other solution state approaches is the ability to use D2O/H2O solvent contrast variation to selectively match out specific parts of a multi-component system. While proteins, nucleic acids, and lipids are readily distinguished in this way, it is not possible to locate different parts of a protein–protein system without the introduction of additional contrast by selective deuteration. Here, we describe new methods by which ‘matchout labelled’ proteins can be produced using Escherichia coli and Pichia pastoris expression systems in high cell-density cultures. The method is designed to produce protein that has a scattering length density that is very close to that of 100% D2O, providing clear contrast when used with hydrogenated partner proteins in a complex. This allows the production of a single sample system for which SANS measurements at different solvent contrasts can be used to distinguish and model the hydrogenated component, the deuterated component, and the whole complex. The approach, which has significant cost advantages, has been extensively tested for both types of expression system.
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Hellebuyck T, Ducatelle R, Bosseler L, Van Caelenberg A, Versnaeyen H, Chiers K, Martel A. Basal cell carcinoma in two Hermann’s tortoises (Testudo hermanni). J Vet Diagn Invest 2016; 28:750-754. [DOI: 10.1177/1040638716668560] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Neoplastic disorders are frequently encountered in the practice of reptile medicine. Herein we report the clinical behavior, antemortem diagnosis, and histopathologic characteristics of a recurrent intraoral keratinizing basal cell carcinoma (BCC) and a metastatic BCC of the carapace in 2 Hermann’s tortoises ( Testudo hermanni). Although squamous cell carcinomas (SCCs) in tortoises show similar predilection sites and gross pathologic features, the BCCs described in our report were characterized by a remarkably fast and highly infiltrative growth in comparison to SCCs. Accordingly, early diagnosis including reliable discrimination from SCC is essential toward the management of this neoplastic entity in tortoises.
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Antonissen G, De Baere S, Devreese M, Van Immerseel F, Martel A, Croubels S. Feed contamination with Fusarium mycotoxins induces a corticosterone stress response in broiler chickens. Poult Sci 2016; 96:14-17. [PMID: 27591283 DOI: 10.3382/ps/pew280] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 02/24/2016] [Accepted: 07/05/2016] [Indexed: 11/20/2022] Open
Abstract
The aim of the present study was to evaluate the effect of the Fusarium mycotoxins deoxynivalenol (DON) and fumonisins (FBs) on the stress response in broiler chickens, using corticosterone (CORT) in plasma as a biomarker. Chickens were fed either a control diet, a DON contaminated diet, a FBs contaminated diet, or a DON and FBs contaminated diet for 15 d at concentrations close to the European Union maximum guidance levels for DON and FBs in poultry. Mean plasma CORT levels were significantly higher in broiler chickens fed a DON contaminated and a DON and FBs contaminated diet compared to birds fed a control diet. A similar trend was observed for animals fed a FBs contaminated diet. Consequently, feeding broilers a diet contaminated with DON and/or FBs induced a CORT stress response, which may indicate a negative effect on animal welfare.
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141
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Mezhoud H, Chantziaras I, Iguer-Ouada M, Moula N, Garmyn A, Martel A, Touati A, Smet A, Haesebrouck F, Boyen F. Presence of antimicrobial resistance in coliform bacteria from hatching broiler eggs with emphasis on ESBL/AmpC-producing bacteria. Avian Pathol 2016; 45:493-500. [DOI: 10.1080/03079457.2016.1167837] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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142
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Spitzen-van der Sluijs A, Martel A, Asselberghs J, Bales EK, Beukema W, Bletz MC, Dalbeck L, Goverse E, Kerres A, Kinet T, Kirst K, Laudelout A, Marin da Fonte LF, Nöllert A, Ohlhoff D, Sabino-Pinto J, Schmidt BR, Speybroeck J, Spikmans F, Steinfartz S, Veith M, Vences M, Wagner N, Pasmans F, Lötters S. Expanding Distribution of Lethal Amphibian Fungus Batrachochytrium salamandrivorans in Europe. Emerg Infect Dis 2016; 22:1286-8. [PMID: 27070102 PMCID: PMC4918153 DOI: 10.3201/eid2207.160109] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Emerging fungal diseases can drive amphibian species to local extinction. During 2010–2016, we examined 1,921 urodeles in 3 European countries. Presence of the chytrid fungus Batrachochytrium salamandrivorans at new locations and in urodeles of different species expands the known geographic and host range of the fungus and underpins its imminent threat to biodiversity.
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Mahu M, De Pauw N, Vande Maele L, Verlinden M, Boyen F, Ducatelle R, Haesebrouck F, Martel A, Pasmans F. Variation in hemolytic activity of Brachyspira hyodysenteriae strains from pigs. Vet Res 2016; 47:66. [PMID: 27338265 PMCID: PMC4917944 DOI: 10.1186/s13567-016-0353-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 06/05/2016] [Indexed: 11/30/2022] Open
Abstract
Brachyspira hyodysenteriae is the primary cause of swine dysentery, which is responsible for major economic losses to the pig industry worldwide. The hemolytic activity of 10 B. hyodysenteriae strains isolated from stools of pigs with mild to mucohemorrhagic diarrhea was compared and seven hemolysis associated genes were sequenced. Hemolysis induced by these strains varied from strong to near absent. One weakly hemolytic B. hyodysenteriae strain showed sequence changes in five hemolysis associated genes (tlyA, tlyB, hemolysin III, hemolysin activation protein and hemolysin III channel protein) resulting in amino acid substitutions. The occurrence of weakly hemolytic strains identifiable as B. hyodysenteriae should be taken into account in swine dysentery diagnostics. The presence of these strains may affect herd dysentery status, with great impact on a farms trading opportunities.
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Rijks JM, Saucedo B, Spitzen-van der Sluijs A, Wilkie GS, van Asten AJAM, van den Broek J, Boonyarittichaikij R, Stege M, van der Sterren F, Martel A, Pasmans F, Hughes J, Gröne A, van Beurden SJ, Kik MJL. Investigation of Amphibian Mortality Events in Wildlife Reveals an On-Going Ranavirus Epidemic in the North of the Netherlands. PLoS One 2016; 11:e0157473. [PMID: 27315226 PMCID: PMC4912076 DOI: 10.1371/journal.pone.0157473] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 05/30/2016] [Indexed: 12/15/2022] Open
Abstract
In the four years following the first detection of ranavirus (genus Ranavirus, family Iridoviridae) infection in Dutch wildlife in 2010, amphibian mortality events were investigated nationwide to detect, characterize and map ranaviruses in amphibians over time, and to establish the affected host species and the clinico-pathological presentation of the disease in these hosts. The ultimate goal was to obtain more insight into ranavirus disease emergence and ecological risk. In total 155 dead amphibians from 52 sites were submitted between 2011 and 2014, and examined using histopathology, immunohistochemistry, virus isolation and molecular genetic characterization. Ranavirus-associated amphibian mortality events occurred at 18 sites (35%), initially only in proximity of the 2010 index site. Specimens belonging to approximately half of the native amphibian species were infected, including the threatened Pelobates fuscus (spadefoot toad). Clustered massive outbreaks involving dead adult specimens and ranavirus genomic identity indicated that one common midwife toad virus (CMTV)-like ranavirus strain is emerging in provinces in the north of the Netherlands. Modelling based on the spatiotemporal pattern of spread showed a high probability that this emerging virus will continue to be detected at new sites (the discrete reproductive power of this outbreak is 0.35). Phylogenetically distinct CMTV-like ranaviruses were found in the south of the Netherlands more recently. In addition to showing that CMTV-like ranaviruses threaten wild amphibian populations not only in Spain but also in the Netherlands, the current spread and risk of establishment reiterate that understanding the underlying causes of CMTV-like ranavirus emergence requires international attention.
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Martel A, Nguyen E, Lassale S. [Bulbar conjunctival osseous choristoma in a 9-year-old girl: Clinical and pathological findings]. J Fr Ophtalmol 2016; 39:586-7. [PMID: 27257111 DOI: 10.1016/j.jfo.2016.02.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2016] [Revised: 02/03/2016] [Accepted: 02/16/2016] [Indexed: 10/21/2022]
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146
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Michiels T, Welby S, Vanrobaeys M, Quinet C, Rouffaer L, Lens L, Martel A, Butaye P. Prevalence ofMycoplasma gallisepticumandMycoplasma synoviaein commercial poultry, racing pigeons and wild birds in Belgium. Avian Pathol 2016; 45:244-52. [DOI: 10.1080/03079457.2016.1145354] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Antonissen G, Van Immerseel F, Pasmans F, Ducatelle R, Janssens GPJ, De Baere S, Mountzouris KC, Su S, Wong EA, De Meulenaer B, Verlinden M, Devreese M, Haesebrouck F, Novak B, Dohnal I, Martel A, Croubels S. Mycotoxins Deoxynivalenol and Fumonisins Alter the Extrinsic Component of Intestinal Barrier in Broiler Chickens. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2015; 63:10846-10855. [PMID: 26632976 DOI: 10.1021/acs.jafc.5b04119] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Deoxynivalenol (DON) and fumonisins (FBs) are secondary metabolites produced by Fusarium fungi that frequently contaminate broiler feed. The aim of this study was to investigate the impact of DON and/or FBs on the intestinal barrier in broiler chickens, more specifically on the mucus layer and antioxidative response to oxidative stress. One-day-old broiler chicks were divided into four groups, each consisting of eight pens of seven birds each, and were fed for 15 days either a control diet, a DON-contaminated diet (4.6 mg DON/kg feed), a FBs-contaminated diet (25.4 mg FB1 + FB2/kg feed), or a DON+FBs-contaminated diet (4.3 mg DON and 22.9 mg FB1 + FB2/kg feed). DON and FBs affected the duodenal mucus layer by suppressing intestinal mucin (MUC) 2 gene expression and altering the mucin monosaccharide composition. Both mycotoxins decreased gene expression of the intestinal zinc transporter (ZnT)-1 and regulated intracellular methionine homeostasis, which are both important for preserving the cell's critical antioxidant activity. Feeding a DON- and/or FBs-contaminated diet, at concentrations close to the European Union maximum guidance levels (5 mg DON and 20 mg FB1 + FB2/kg feed) changes the intestinal mucus layer and several intestinal epithelial antioxidative mechanisms.
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148
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Van Rooij P, Martel A, Haesebrouck F, Pasmans F. Amphibian chytridiomycosis: a review with focus on fungus-host interactions. Vet Res 2015; 46:137. [PMID: 26607488 PMCID: PMC4660679 DOI: 10.1186/s13567-015-0266-0] [Citation(s) in RCA: 114] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 10/05/2015] [Indexed: 01/30/2023] Open
Abstract
Amphibian declines and extinctions are emblematic for the current sixth mass extinction event. Infectious drivers of these declines include the recently emerged fungal pathogens Batrachochytrium dendrobatidis and Batrachochytrium salamandrivorans (Chytridiomycota). The skin disease caused by these fungi is named chytridiomycosis and affects the vital function of amphibian skin. Not all amphibians respond equally to infection and host responses might range from resistant, over tolerant to susceptible. The clinical outcome of infection is highly dependent on the amphibian host, the fungal virulence and environmental determinants. B. dendrobatidis infects the skin of a large range of anurans, urodeles and caecilians, whereas to date the host range of B. salamandrivorans seems limited to urodeles. So far, the epidemic of B. dendrobatidis is mainly limited to Australian, neotropical, South European and West American amphibians, while for B. salamandrivorans it is limited to European salamanders. Other striking differences between both fungi include gross pathology and thermal preferences. With this review we aim to provide the reader with a state-of-the art of host-pathogen interactions for both fungi, in which new data pertaining to the interaction of B. dendrobatidis and B. salamandrivorans with the host’s skin are integrated. Furthermore, we pinpoint areas in which more detailed studies are necessary or which have not received the attention they merit.
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149
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Hellebuyck T, Van Caelenberg A, Antonissen G, Haesendonck R, Martel A. Aviair bornavirus en kliermaagdilatatiesyndroom bij psittaciformen. VLAAMS DIERGEN TIJDS 2015. [DOI: 10.21825/vdt.v84i5.16591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Aviair bornavirus (ABV) is het primaire etiologische agens dat het kliermaagdilatatiesyndroom (KDS) veroorzaakt bij psittaciformen. In tegenstelling tot wat oorspronkelijk over KDS verondersteld werd, blijkt ABV-infectie algemeen voor te komen bij psittaciformen en niet steeds aanleiding te geven tot klinische ziekte. In dit artikel wordt een overzicht gegeven van de huidige kennis van ABV. De diagnose, behandeling en het onder controle houden van KDS bij psittaciformen worden beschreven. Het stellen van een ante-mortemdiagnose van ABV als oorzaak van KDS vormt een uitdaging. Voornamelijk het correleren van de ABV-status aan het waargenomen klinische beeld is niet steeds vanzelfsprekend. De nood aan betere diagnostische methoden met een hoge sensitiviteit en specificiteit om ABV-infectie te detecteren, dringt zich dan ook op.
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150
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Antonissen G, Croubels S, Pasmans F, Ducatelle R, Eeckhaut V, Devreese M, Verlinden M, Haesebrouck F, Eeckhout M, De Saeger S, Antlinger B, Novak B, Martel A, Van Immerseel F. Fumonisins affect the intestinal microbial homeostasis in broiler chickens, predisposing to necrotic enteritis. Vet Res 2015; 46:98. [PMID: 26394675 PMCID: PMC4579638 DOI: 10.1186/s13567-015-0234-8] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 07/28/2015] [Indexed: 11/10/2022] Open
Abstract
Fumonisins (FBs) are mycotoxins produced by Fusarium fungi. This study aimed to investigate the effect of these feed contaminants on the intestinal morphology and microbiota composition, and to evaluate whether FBs predispose broilers to necrotic enteritis. One-day-old broiler chicks were divided into a group fed a control diet, and a group fed a FBs contaminated diet (18.6 mg FB1+FB2/kg feed). A significant increase in the plasma sphinganine/sphingosine ratio in the FBs-treated group (0.21 ± 0.016) compared to the control (0.14 ± 0.014) indicated disturbance of the sphingolipid biosynthesis. Furthermore, villus height and crypt depth of the ileum was significantly reduced by FBs. Denaturing gradient gel electrophoresis showed a shift in the microbiota composition in the ileum in the FBs group compared to the control. A reduced presence of low-GC containing operational taxonomic units in ileal digesta of birds exposed to FBs was demonstrated, and identified as a reduced abundance of Candidatus Savagella and Lactobaccilus spp. Quantification of total Clostridium perfringens in these ileal samples, previous to experimental infection, using cpa gene (alpha toxin) quantification by qPCR showed an increase in C. perfringens in chickens fed a FBs contaminated diet compared to control (7.5 ± 0.30 versus 6.3 ± 0.24 log10 copies/g intestinal content). After C. perfringens challenge, a higher percentage of birds developed subclinical necrotic enteritis in the group fed a FBs contaminated diet as compared to the control (44.9 ± 2.22% versus 29.8 ± 5.46%).
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